PySpy Stack Viewer – “Where’s my Python process right now?”
A simple VS Code extension to instantly locate your Python process and see a live stack trace inside the editor.
▶ Demo: One-click stack trace viewer in VS Code
TL;DR
✅ Find any long-running Python process
✅ Click once – instantly view the live stack trace inside VS Code
✅ Click a frame – jump to the exact code line
✅ No terminal needed – no PID hunting, no extra windows
Why you might need it 🤕
The Pain
You launched a script / worker / web-server that has now been
“running forever”.
The log is quiet, CPU is low, you think it’s not hung …
but you have no idea where it is inside the code.
Existing Tool py-spy dump --pid 12345can show the stack-trace, but:
You have to look up the PID yourself
The output is in the terminal – not linked to files
Every refresh → new command / new window
What this extension gives you 🚀
All the features shown in the demo above:
One-click attach to any Python process
Sticky header with process name, PID, and command line
Tree view of the live Python stack
Click a frame to jump to the source
Manual refresh & frame order toggle
Quick start 🛠️
1. Install
📦 From the Marketplace: search for “PySpy Stack Viewer” (extension ID: pyspy-stack-viewer)
Or install manually via .vsix: Extensions ▸ ⋯ ▸ Install from VSIX
2. Using the extension
Click the side icon to open the panel.
Three toolbar buttons appear:
Button
Action
Description
🔍
Attach
Pick a running Python process. The list shows PID + command, with full command line on hover.
↻
Refresh
See the current stack trace of the process. The top frame is where your code is right now.
⇄
Toggle order
Switch between bottom-to-top and top-to-bottom stack display.
When the process ends:
The tree view doesn’t disappear immediately (to avoid disrupting your inspection).
Press ↻ to refresh – you’ll then see a “Process ended” message and the tree will clear.
Under the hood 🔧
On first use the extension installs py-spy 0.4.0 into VS Code’s
private storage – you don’t need to pre-install anything.
Requires Python 3 on your PATH (or configured interpreter in
Python for VS Code).
The same interpreter is used to pip install py-spy.
Needs permission to ptrace the target process. On Linux that means:
Same user – works out of the box when both VS Code and the process run
under you.
Different users / sudo – run VS Code with the same privileges or lower
ptrace_scope.
Limitations & tips 📎
Each refresh is a snapshot – there’s no auto-polling (by design, zero overhead).
If you want a new view ➜ press ↻.
Pure-C / native threads won’t show Python frames (that’s a CPython limit).
If the list shows no Python processes, make sure your remote / WSL
session sees them (they must be on the same machine).
Contributing / Issues 🤝
Found a bug? Need another feature? PRs are welcome.
Please include:
to open the panel.